SOLUTION: 1) Combine: [(2/5)x2 + (3/4)x + 5] – [(2/3)x2 – (2/3)x – 6] I'm unsure how to solve this question with the brackets thanks

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: 1) Combine: [(2/5)x2 + (3/4)x + 5] – [(2/3)x2 – (2/3)x – 6] I'm unsure how to solve this question with the brackets thanks      Log On


   



Question 176041: 1) Combine: [(2/5)x2 + (3/4)x + 5] – [(2/3)x2 – (2/3)x – 6]
I'm unsure how to solve this question with the brackets
thanks

Found 2 solutions by user_dude2008, josmiceli:
Answer by user_dude2008(1862) About Me  (Show Source):
You can put this solution on YOUR website!
Note: x^2 means x squared

[(2/5)x^2 + (3/4)x + 5] – [(2/3)x^2 – (2/3)x – 6]=(2/5)x^2 + (3/4)x + 5 – (2/3)x^2 + (2/3)x + 6
                                                 =[(2/5)x^2– (2/3)x^2] + [(3/4)x + (2/3)x ] + [5  + 6]
                                                 =-(4/15)x^2 + (17/12)x + 11



Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!

When you have lots of ( )s and [ ]s, it can get confusing
One way to help with this is to say
A+=+%282%2F5%29x%5E2+%2B+%283%2F4%29x+%2B+5
B+=+%282%2F3%29x%5E2+-+%282%2F3%29x+-+6
Now rewrite the expression
A+-+B
What's -B?
-B+=+-%282%2F3%29x%5E2+%2B+%282%2F3%29x+%2B+6
Now combine like terms
A+-+B+=+%282%2F5%29x%5E2+-+%282%2F3%29x%5E2+%2B+%283%2F4%29x+%2B+%282%2F3%29x+%2B+5+%2B+6
A+-+B+=+%286%2F15%29x%5E2+-+%2810%2F15%29x%5E2+%2B+%289%2F12%29x+%2B+%288%2F12%29x+%2B+11
A+-+B+=+-%284%2F15%29x%5E2+%2B+%2817%2F12%29x+%2B+11